SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ea8c05c6810b252dd45eba3548fd3a09a67f972af67e018de4bbfc32ac22230' 
  AND token = 'w7TeqGl7E5WDWtn4CywqWB+JzPTXK7CtXeD2WAb2HDY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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