SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6be16e63a9c0c5063181917941c519438ab465575514a1b85027d9d77745fb5b' 
  AND token = 'IPgVT8r7m5zxkCQdwbRy7dsOwUY893RecfaCh+pgQrY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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