SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09028b81274ce314df77334f1583a85d334bd2c3db84d11b1daead1198319f77' 
  AND token = 'ol4yYavSTzPIFzClhDXnXFgdrp+BYo5qpvRVkT/LiSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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