SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd908d7ddba4a951a0784969dec48a0d365dcd6ccc7615a04af864e59392dfd3' 
  AND token = '5jL8MiE49cRgHJXgzNrgQ8rCBybMbAodLEIfhYcpQfk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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