SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94d31b997c1ae7f2d7c46aeb7a6c81e8b09c173f56c1bfe7ef3eb9a6a554ecbd' 
  AND token = 'OxWoODMyYeS9UHGRSiueKVa21rqoPWiCD2AqmF82W68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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