SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '927ada8942e08453efc2af95c88827ed186fbb6198d70b4a3333e6abe2b7cbfe' 
  AND token = 'LEMbVf2fHE4oIy7F4+MEjwDGu/+BmCxdtVJaxbuJaeM=' 
  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"
    }
  }
}