SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '252764b7ec2d5b32469d4eb1e98fd63ca2ebad800d596baf3f4cf46c05dee759' 
  AND token = 'YYgR13tA163mGZ5WXUuJukJDmsJACWOPUTGdU8+UlVU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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