SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08a0a230d01f9d8d3431508ff8120d4b99012bff98f79609aaea7cfe3eda7fbb' 
  AND token = 'VpML3uPHbAvA+RgBqgru6ZKs5aQu8e42zElaWfcsi/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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