SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc91386de827b116d9476b3f9d4b0655bdb640d430512016f80427da65262e35' 
  AND token = 'pIKJsMh/72JULiopOnozwRESTInOijIOeUU1bJpPpJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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