SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd368a3ab5346b6b9141b8c69ee40e2b970c24162986b5082c9e0858d59fa9c25' 
  AND token = 'bX6uPLWMC8kCvIDm8/2k1cI2/RPpLeXnI91cm13oQ5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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