SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ffa10bf36d1b3f7fbe65935fc7d19d01b10d1bf45ff2261102810fa972e7b0d' 
  AND token = 'KJpLMnUrc++q8QtnHo7OCxHpDj8ZT1xXhqQ6wgF/ioc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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