SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f2405e24f5a618c85e268c453a846d44bc212d8da12376702b684dc4a395d20' 
  AND token = '0zKG5c22sJP/IeKk+6JFJJgQ5vLyaDpHmmItftlSxSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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