SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cf1a447367fcb1ff2a8fbef90f03b7dbc425bf00adeccdc4af6b95e5710d444' 
  AND token = 'lvnsDi1UisDXlIH/qO4GKNg3kVOCeJN1dEJzChwIzF0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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