SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd1631fd89bbc43a9f665fc311afcaa113f020981c200da1fe7e21b16e241561b' 
  AND token = 'hbgSFY91Tbyc/18bAyzFHZCYPJRhSp4vfXGOb40ckzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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