SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dda57e4e4b5da714a72d3bd881cd9fa91b5e4ae486f39ff255911944d624ddf9' 
  AND token = 'F5gttx1/yancGKL0zh53AHlO6zR3GlqAJK5Sc+GoBiY=' 
  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"
    }
  }
}