SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70e1bc2878ba531794394f8f7b37a55f9af71585bbfb2475f4635f50165b624f' 
  AND token = 'HA1mFPld7oVr49J5gGrTLB7tFr8Y3B4BIx91XTIrCYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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