SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40bd0fb596e77b0ba6c275449b7ac358a550a2c68fa87895c1871af4fc585414' 
  AND token = 'Wc6/229SnNTL+ukonsRCeZ9+gdan8GT8rMgghzRo5Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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