SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b6d267f1fa626d72ac5da0a758e01441a0c9ffcfae47c73c4411abe38c6de1c' 
  AND token = 'Zv1BLCzQtxN9hyJOL6OGR5vgkL18tAJ8xmBDboubpyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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