SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e676a74abeeec7cce204ed5476fde57c35d3aed44bd360df6fd7fabd5cd983f' 
  AND token = 'q/MK0jvzZXIrs9KZSpY3Inz6ayvaz6Zs1ApEeE2L7fA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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