SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85de63557d48d15b30e487eb294e58a85aaaaf8a2bcc7ff55f357fdee6e36619' 
  AND token = 'MlU/tcqycTKDrlbQR5vpkaz8ACSXeZHJCnlqbQ5axAU=' 
  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"
    }
  }
}