SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'da3839b9f250a0b564ac0e435c69fecc9fa5591097c16bb4c4d7a222de022876' 
  AND token = 'KVYoyXejj9i7uC4xUCsqBWAJ2yNTNHvgNm23n1oY078=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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