SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b20b4165a22bef2e9647d33e2da7fdca0a7924ddd39609f2590e97e939dcbbc' 
  AND token = 'O7K/RglKLQXmN5zeyywReul29rHN7lYPDpHwAaHBstE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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