SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '289f6222cac31d3f3bc27aa81dba53d630fa571ae46768b16f99e5d7ce197ee9' 
  AND token = 'kJFDr3unEnWFM5yKOQuYkccQarknxzYybSpDzkYLrTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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