SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd4cf294d93ba63f9113e9760594a2451fcebab85d17c2723684f44b538c3971' 
  AND token = 'M8eIyrGg7PmFLPH846HjyrQ3AD8Yyown2ITS5kiP98U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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