SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02d77f91be73cc51996c91c86c512f26d3c4e0ad412b5759f920155cfa378e2a' 
  AND token = 'yhwopQUZa69D30quxMB+EEoFFvUzEWWt3MPIXKUpGlI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}