SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f63a3a1518bc4803ac7db9d84871463485cd0959278d5cc4eab46e1403f41ce' 
  AND token = 'bxQhQs7QVVrx1u4Mv3jwZlL+ETGzmYq3PxLG/0iqm9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}