SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ff6ada293d46c6a67d5979f7404ec9dba4e248e199e5200d8ddbf1f3083cd61' 
  AND token = 'db+XwMS/Amu/21YDY/IR+a9+sg6AFXbvHL/Fnxojuq8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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