SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b48495d54096be7db6c47bf60536040c1d11ac62af7561f396eef0be0383f740' 
  AND token = 'uhk45i1zmm/Q8n1WH/nTfdB64FQhRKhJHcZojaN/A5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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