SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d50ef5c8b0b3f7fa8de132786d1fd8c9c607a722a7e68d8f0fac83531e40e95' 
  AND token = 'HFn6RWCnIHFFsuEsS//G7hC4aIV3+4+9bBCZOoCFKlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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