SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff726e63dbd70a449c3b0f776f372f6e17afcf0a14f7817b6dbbb5999eb8ab7d' 
  AND token = 'Vwspu+EEWibyLKSyodTaMreHPdFmTDG0ekvGuwKxD+g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}