SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6057bc4e921c07f6b08e0251b1a11996c1a3817f0f5ad407130aa23d30a8b5fc' 
  AND token = 'FHFWQglyjYhwI1WZCczmQuD1SKwUeOC+wqlFjhBAgiQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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