SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f34bbec96665e1b1a147954911908e9cedd7b03c3c09131fc3220ad795a4414d' 
  AND token = '0+JfjD7cCLRGB5iCy/g0RGFrrDgDJ4VT62rwD7LxV2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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