SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c6efb90837b4832941d3549728e706ec0f46457f06137bff94e026360780834' 
  AND token = 'nbMwlYV455kQi5dNVbXFUaW1yYpRrKXBQWDqGrK9sgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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