SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f593696ad7367d4479cfb3389142201c995f8385ac970285f68fdbcebb0d763' 
  AND token = 'jgIsYUZrpviBLgccjMHkNVdlNZ258vb+IxOesFTxuTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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