SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99290056b67a061dd7ddca625aed98d9352881385349bbea7fe35673e98c9807' 
  AND token = 'QURd9O6hFPY7ybhdBdFQyIiLN2FvEMmQmxpHqVxuiD8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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