SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26d3d9d983321cbbf5f080c4b1dbf0ea9699827df0d3cfba414591574d57323a' 
  AND token = '0ZsyUmJ8wTvcblmOp7yvVLIRrqRi0dLS3J0aTOiQ0FE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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