SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef3c0322380f4ec2d74aa90be53281765baffb25c80798a8d6309e9ddf6ff6d8' 
  AND token = 'km8jS2YPnX4u27ChvpB1fQ2koDZsvx55qzc/rVEYnHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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