SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d4c7591b03952c3612e5b061b78b713477e56c5ccfc62d13a1cded9a3455a44' 
  AND token = 'j1FvItbyXRgJ8imFxEeFIcnJystyw9tF+oEfhgIYIoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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