SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ebe559bceb95539804d3975ea5f3571ee7453f293314160acbaa32ec202b17ad' 
  AND token = 'I+p88LIXtYnjkyNpgsdwc5OKFnIyruPunp12nc0QMTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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