SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7d440af8eee3e90189a312c54f1c4d13da64ef73ecf17e43ec7781b78e4b9f1f' 
  AND token = 'HmDsSRAnBwWq8u0yEjQ3K9ZSUMMVEQAbbt/KcN/7ejI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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