SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '44ed0def1a8c43b5725da62b2761fd22e9a4a9f183badb721394ec77cca3e54e' 
  AND token = 'rOsBzD3KHBPQW2BNe6ZYP8F4Xk163b4ut3R+jaP4wnY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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