SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae83adde0a7d29d81b7f76bbd8bc2b688875e19ec5882d7b64545ade4291eb65' 
  AND token = 'xdAKRQXWpa9BpSytlBPrjrwxJ8tAMjWLlj2z7tqxF/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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