SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3d88c2262b33174c331e73b758aef9fd367f4466e572aa1802a89e31d48c882' 
  AND token = 'da0cMFISdDIPVYcIxuwcGjiIdBnc/GPXWvkAt31rYeI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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