SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c04c033b54ebd82e976d93e3121c56caf1a708dd5d59bd95f914f7a861cd329c' 
  AND token = 'vr285X7DXWPZPw4ZZ3FE40qjGzSBWXMHQOauvdYLA/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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