SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44738dae243ed32c1ff3eda388d364f9c35561377575f334a0e3fea1780b3cc9' 
  AND token = 'rBG5FsUXOESBBMankHqd707OHEgUHoVqOnKf1Op9UUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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