SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2e65967b236f64bd849fa79caf17d64af2d474b5f7fc6ea0ded3208ead9510b' 
  AND token = 'F+S6UBKCCEKOvgiZUJZjmJmkmqKAwUc+rD+AA9u/ILQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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