SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bb60afa0c6ff596ff95ac90a1649a44212770e3573fb2c43671b97e7e2a8e437' 
  AND token = 'KCQ+SvLCIPjLdZM41u/kt2YaBm/URyUZjPEbZcZ2m90=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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