SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956e3051a9c0a34f21dc99459484898b5153c53f58d0b9cab56a4276f25fd213' 
  AND token = 'vdxHxjzJgGG8qgeI/WhVbw7dCBhszamaRkb2dod+cp0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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