SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4abe8db409399e212c7c218fd00bd35b10e543ea531d788eaf8c6311f5082fc0' 
  AND token = 'eH8UIhG1QMHgSE08SDSMG+qLOxS4FUbqk97xK9ykubI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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