SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2860f415ed92e2363ccfe54e36450a00f37cf03afdb1ea5a79878a301793fe64' 
  AND token = 'BFbhCj4vq8Bb6Jr9CdcrWcgOTNSUP5XcmQnZ79sCO2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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