SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37334ef5e55ee5fcdbc0ea0e92ca437c2a690958752665ff336349adcb502bb7' 
  AND token = 'rZJw3RgvRt2pnenZ4gTFUvJjw4qMdWZJTcmGg6a+14A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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