SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33f7cc27b3e16aad00b7987c6f20217ad690a96fb1a872e3d291142e6e15e959' 
  AND token = 'k1YThPDAVpxE7lP1vGZkN4rk/JLY+IHw6iCjKIrxnHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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