SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '659018a9c0abbffa55f5929a6078e4fb89a7c64e74541eef10a901cbc888707b' 
  AND token = '764Zf13KELpcOwmipLBEBCbKbxT2dezVP5ko85B3gaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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