SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68b83aa4f8b97b93badf638b717adc1874817d1a1edd792749cdaddadcea4c75' 
  AND token = 'UXqkYEAdwAWHXs5q2wf3JJqz07qNuN2gUxURd1Av7o4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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