SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83fa9c04e2e4077b6ace482d7aaa21f725b53eda2fcf983525af60fc3f0ded33' 
  AND token = '+HWhSvnfZAbGO+eqS2qGHEJuhiIoB+gAnY+zMDhN8Ss=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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