SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b878802275533409d8cbe5c6dd37d210018aec5ff3623adc2755e308738e4ca' 
  AND token = 'Td6sHPgOO0IUj/PUELGwakVK5tixraPxTgIq+hIQwlw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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