SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb86744da8b20c2794ee15ce616e6244d7a4b9002a69dab7378ffedda0c4d124' 
  AND token = 'GPf+WYCBDeltgAYQnHKaTbgxuCgpI1vFPhiMWxq7B1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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