SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '396acf7be8c2e18f391a753b7958283296b4294bd2c77840028cbe43d8156083' 
  AND token = 'uDOMFwXamG88o9w5ngCSJLG5A3N/uQebFz31vtHgH+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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