SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '804943396125e64fdc60333519071891bbfe902deff480625ad1da705430c810' 
  AND token = 'zaR6jtfD/azwc0F/bHTgzeyp9ALFSjrck0BgS/L/M5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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