SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd83a349b88098d6f9a3803deb3a4f80ad794f968b7c3cea809eb45a9e356a162' 
  AND token = '307pZ8IWyqIHr+k6YbnzVWF2bi8Ypiy6OPvLJ/NIk5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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