SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7612e4a14060ecc0771631d0bd65b2fd54d62db9d39f3a6d015be771af12da58' 
  AND token = 'XUs2eZEsByw7JDYRSlnUCmv+LNjIhLjf/P6IkDACZNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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