SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd81e6c18a6e249e102f82d6ca88a0f1cebe46c96a58e53ebccff08de52f7ed2b' 
  AND token = 'DrVhprclqrkRuKqBtsJ/6YgQwpQ78LHuWHWu5KJPqDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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