SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01c0f55609c158bcfed405e433a1c8d676a49a679999584df8122f494dd0c57b' 
  AND token = 'mMmJQT3k1fF18ox/WMRbM69iNqkfJW3zuf9eOqmfLdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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