SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cbeb854a21f9901455258ae89c847a32940cb5f112a77b9adfb8e0b0a46b6dd8' 
  AND token = 'QxLKZpRIo0Aj6Nn3SHU3fH2novhGmofXlXWYTQvsTXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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