SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eea64f222d7db463ed888a43cf191d5e9ca1a5f24b74d0011296e6d3979b560f' 
  AND token = '461/rgM+qrby7OjeYI5A2gsVwpMlh7CBx1Btt6UnomQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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