SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8fb25782de739c0ed01175e157a90330a640ad551f5be30ded7cf0dfe1da1a65' 
  AND token = 'NZ4UyPv53XGpxhvSiqCvEjJso4gs8n04wGqVp6nRhFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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