SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '56c9651b49481bb8f268fcb76953a76fb37849f1fdbef1b6d51f35365f840d67' 
  AND token = 'vMdmP0BXRGZpVuob7uAwBW+gAZLvd1ox79NkNew3s84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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