SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6784f5bfcb4b64078fc1c7d4bfb75698ef4b13a0670eee552a72fc594da2597c' 
  AND token = 'P7JNPybkckT4BlOqXGBhtfDDyUtTf2ZF5o0y1hU8cRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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