SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cce9934dde81d7b8e7273513e20968e36119b39ca33b966120507c27523ce7ad' 
  AND token = '1Rf0VniVTu9ZZwsSsKY9tiOctHndh5xCCxNzc6zB/cw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}