SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a30cbc0eb2c569b33a6d9c2e8f8368e18fae10029c43ffefee60b7aa3f4187e9' 
  AND token = '/zpKlzvrDDdG74BibmY0BDumMnBEyA3CmDPNFlfAMTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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