SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9b28a7060e5e30f69828358d4f5d823a113b62942476faad7f93056d6d9efe3' 
  AND token = '7HySiuYiRaK5k/J/Vc/V2vfvZQ5aRI+a+A2InOJlGOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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