SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3355e325c6cfe6b3272093b926b35e4e6990039e75c56278af4b6302860825f6' 
  AND token = 'uILrulJdTgQ/JBggNo/toCeVyspCqOckGlzooEuYOx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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