SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '668f872f9cdf51f57af23b92a63143a5bb5968a051416cdb75d348978b7cdf0f' 
  AND token = 'J1lChKFwOPAywEhK8U2CoHUhIeL0aAMrqMZJAzyJGUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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