SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8c23cdbeeb027e80765862f1868a355a74e680f9c4ecbcf08006a5700a081b1' 
  AND token = 'v00iMtBNLESNWczrKAJTlnIRekOjKeE0tc87IdCcpVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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