SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a43ae0e63ad385f16b4dd7d23db4028d33e58deaed0e81872700dad2230b160' 
  AND token = 'Fc29f75S5JLopXWymGylxnz67mnaTyicA37EbvlOQrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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