SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f044c9cd5f668a135fae400acb6761717330400ad38bfac7bda30b3910cbe603' 
  AND token = 'dZS9NMsw/JC6Zw2cd7RFsxuotWr4xdvtkC6qTtD5JJg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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