SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a80fd02bbe846008b9e2944e44ba4798bc54e167ebea6218a97594d695375568' 
  AND token = 'SdYSLvdnw8qLhiWKLmPqEziEE2cQ7bpJ79w2rcSmq+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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